The squad were having “visual training”． One smart recruit was asked by the officer to count how many men composed a digging party in a distant field．The party was so faraway that the men appeared as mere dots， but unhesitatinglythe recruit replied： 

　　“Sixteen men and a sergeant，sir．” 

　　“Right；but how do you know there's a sergeant there？” 

　　“He's not doing any digging， sir．” 

　　视力训练 

　　班里正在进行“视力训练”。一个聪明伶俐的新兵被班长叫出来数远处旷野上采掘队的人数。采掘队在很远的地方，那些人看起来只是一些小点儿。但是这个新兵毫不犹豫地回答。 

　　“十六个兵外加一个中士，长官。” 

　　“正确，可是你怎么知道那儿有一个中士？” 

　　“他不干活，长官。”